[Rdo-list] Outbound packet traffic with nova-network

[Michael Solberg]

Hi list.

I'm having some trouble with my network setup and I thought maybe the 
group could help.  I have three compute nodes with two network 
interfaces.  There's a private 192.168.32.0/24 network (fixed range) on 
eth1 and a 10.17.12.128/25 network (floating range) on eth0 on these nodes.

Networking works as expected.  Connectivity is good on the 192 network 
and traffic is forwarded from the floating range inbound to the fixed 
range correctly.  That is, I can ssh into an instance from the outside 
world using the floating address.  However, when traffic is leaving the 
instance, it doesn't seem to get translated.  Here's a concrete example:

Instance has a fixed address of 192.168.32.4.
Instance is assigned a floating address of 10.17.12.139.
Instance is running on a hypervisor with the address 10.17.12.12.

Pings from the instance to 10.17.12.12 return fine, but pings from the 
instance out to the internet don't work.  When I run a tcpdump, I see 
that the pings reach the destination with the source address set to 
192.168.32.4:

[root at 10.17.12.11 ~]# tcpdump -n -i eth0 icmp
tcpdump: WARNING: eth0: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
23:55:38.238739 IP 192.168.32.4 > 10.17.12.11: ICMP echo request, id 
45321, seq 1, length 64
23:55:38.238774 IP 10.17.12.11 > 192.168.32.4: ICMP echo reply, id 
45321, seq 1, length 64

Is this expected?  If so, is there any way to get nova-network to 
translate the outbound traffic so that it looks like it's coming from 
10.17.12.139 instead of 192.168.32.4?

Thanks.

Michael.
-- 
Michael Solberg
Principal Architect, Red Hat, Inc.